CN111059096B - A structure of hydraulic back-to-center locking actuating cylinder - Google Patents

Abstract

The invention relates to a hydraulic centering locking actuating cylinder structure, which comprises an actuating cylinder casing, a cylinder cover and a piston rod. The piston of the piston rod divides the inner cavity of the actuating cylinder casing into a front chamber and a rear chamber. The structure of the centering locking actuating cylinder also includes a centering hydraulic oil flow channel and a centering actuating rod opened in the side wall of the actuating cylinder housing, and the inner end of the centering actuating rod is inserted into the centering hydraulic oil In the flow channel, the outer end is fixedly connected with the outer end of the piston rod through the connecting bracket, and acts synchronously with the piston rod. The inner blocking section and the outer center-returning sealing ring divide the return-to-center hydraulic oil flow channel into the front-cavity sub-center-return hydraulic oil flow channel and the rear-cavity sub-center-return hydraulic oil flow channel, which are respectively communicated with the external tank. The segment is synchronized with the position of the piston. Compared with the prior art, the present invention has the advantages of centering balance, convenient control, simple structure, and avoiding wear and tear.

Description

A structure of hydraulic back-to-center locking actuating cylinder

technical field

The invention relates to the field of engine hydraulic cylinders, in particular to a hydraulic centering locking actuating cylinder structure.

Background technique

The traditional hydraulic actuator for launching nozzle has no emergency return function, which does not meet the safety requirements of thrust vectoring nozzle control. Therefore, it is necessary to design an actuator structure with an emergency return-to-center locking function, so that the piston of the vector nozzle actuator can stop at a certain intermediate position when the ESC fails, so as to ensure that multiple The nozzle controlled by the type actuator can return to a safe neutral position, thereby ensuring the safe and reliable operation of the engine.

The paper "Research on the Mechanism and Application of the Wall Hole Back-to-Central Hydraulic Actuator" (Zhu Kangwu. Chinese Journal of Mechanical Engineering, 2018, 54(10): 225-232) proposes a wall-hole back-to-centre hydraulic actuator. At the same time, high-pressure oil is supplied to push the piston to the middle of the actuating cylinder housing where there is a center return hole, and the oil flows back to the oil tank through the center return hole. The wear of the sealing ring increases the internal leakage and affects the performance of the actuator.

The Chinese patent "An Emergency Centering Hydraulic Actuator" (Publication No. CN101451556A) designs a centering structure including an active piston, an emergency piston and a support rod. The structure is relatively complex and the actuator works in a limited space. The range of travel is small.

The US patent "Fall-safe Electric Hydraulic Actuator" (Patent No. US 005950427A) resets the actuator to the neutral position through the springs installed in the two cavities of the actuator. Its structure is relatively complicated, and it also needs to be equipped with a spare controller. , the system is complex and redundant, and it is not suitable for the aerospace field with strict space and weight constraints.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a hydraulic centering locking actuating cylinder structure in order to overcome the above-mentioned defects of the prior art.

The object of the present invention can be realized through the following technical solutions:

A hydraulic center locking actuating cylinder structure comprises an actuating cylinder casing, a cylinder head and a piston rod, the piston of the piston rod divides the inner cavity of the actuating cylinder casing into a front chamber and a rear chamber, the hydraulic centering locking The tight actuating cylinder structure also includes a centering hydraulic oil flow channel and a centering actuating rod opened in the side wall of the actuating cylinder housing, and the inner end of the centering actuating rod is inserted into the centering hydraulic oil flow channel, The outer end is fixedly connected with the outer end of the piston rod through the connecting bracket, and moves synchronously with the piston rod. The blocking section and the external return-to-center sealing ring divide the return-to-center hydraulic oil flow channel into the front-cavity sub-center-return hydraulic oil flow channel and the rear-cavity sub-center-return hydraulic oil flow channel, which are respectively communicated with the external tank. location sync.

The rear cavity communicates with the external high-pressure oil source through the oil inlet hole of the rear cavity, and communicates with the hydraulic oil flow channel of the sub-center return of the rear cavity through the oil outlet hole of the rear cavity. A middle hole, the side wall of the actuating cylinder casing is provided with a first actuating cylinder casing middle hole that communicates with the external oil tank, the external high-pressure oil source, the oil inlet hole of the rear cavity, the rear cavity, The rear cavity oil outlet hole, the rear cavity sub-center return hydraulic oil flow channel, the inner end inlet of the center return actuating rod, the first center return hole, the first actuating cylinder housing center return hole and the external oil tank are circulated and communicated with each other to form the rear cavity Hydraulic return loop.

The front cavity communicates with the external high-pressure oil source through the oil inlet hole of the front cavity, and communicates with the hydraulic oil flow passage of the sub-center return of the front cavity through the oil outlet hole of the front cavity opened on the cylinder head, and the oil outlet hole of the front cavity passes through The actuating rod oil inlet hole opened on the middle side wall of the center-returning actuating rod communicates with the outer end of the inner channel of the center-returning actuating rod, and the inner end of the inner channel of the center-returning actuating rod passes through the side wall of the center-returning actuating rod. The second center return hole on the upper part of the cylinder and the second center return hole of the cylinder shell opened on the side wall of the cylinder shell are communicated with the external oil tank. The external high pressure oil source, the front cavity oil inlet hole, the front cavity , Front chamber oil outlet, front chamber sub-center return hydraulic oil flow channel, inner channel of center return actuating rod, second center return hole, second actuating cylinder housing center return hole and external oil tank are circulated and communicated with each other to form front chamber hydraulic pressure Back to the middle ring road.

A sealing groove for placing the middle-returning sealing ring is opened in the middle-returning hydraulic oil flow channel.

The location of the sealing groove is located between the center return hole of the first actuating cylinder housing and the center return hole of the second actuating cylinder housing as the center return position.

The connecting bracket is fastened with the piston rod by pressing plates and screws.

The outer end of the centering actuating rod is blocked by a hydraulic plug.

The centering hydraulic oil flow channel is provided with a guide rod sealing ring at the position of the insertion port of the centering actuating rod.

When the piston rod travels to the center position, the force of the piston is balanced and maintained at the center position.

Compared with the prior art, the present invention has the following advantages:

The invention can complete the automatic centering function of the piston rod of the actuator under the condition of failure and power failure only by designing the structure of the actuator casing and adding the centering guide rod structure, and the structure is simple and the working parts are few. reliability. Compared with the back-to-center form in which the wall hole and the working chamber are directly connected, the wear of the piston seal ring is avoided, and the actuator can still have better working characteristics during long-term operation.

Description of drawings

FIG. 1 is a schematic structural diagram of the hydraulic centering locking actuating cylinder of the present invention.

FIG. 2 is a partial enlarged view of the structure of the centering hole when the present invention is in the centering position.

3 is a partial enlarged view of the place where the oil flows through the oil hole of the cylinder head and enters the centering guide rod when the present invention is in the centering position.

FIG. 4 is a control principle diagram of the present invention.

Description of the marks in the figure:

1. Actuating cylinder housing, 2. Cylinder head, 3. Piston rod, 4. Connecting bracket, 5. Pressure plate, 6. Hydraulic plug, 7. Centering actuating rod, 8. Guide rod sealing ring, 9. Back-to-center sealing ring, 11. Oil inlet hole of rear cavity, 12. Oil inlet hole of front cavity, 13. Oil outlet hole of rear cavity, 14. Hydraulic oil flow passage of rear cavity sub-center return, 15. Return of first actuating cylinder shell Middle hole, 16. Middle hole of second actuating cylinder housing, 21. Oil outlet hole of front cavity, 22. Hydraulic oil flow channel of front cavity sub-center return, 71. Oil inlet hole of actuating rod, 72. Centering action Rod internal passage, 73, Inlet of inner end of return actuating rod, 74, Second return hole, 75, First return hole, 100, Pump, 101, Relief valve, 102, Servo valve, 103, Solenoid Valve, 104, Conversion valve spool, 105, Check valve, 106, External tank.

Detailed ways

The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

Example

As shown in FIGS. 1-3 , the present invention provides a hydraulic center locking actuating cylinder structure, including an actuating cylinder housing 1 , a cylinder head 2 , a piston rod 3 , a connecting bracket 4 , a pressure plate 5 , and a hydraulic plug 6 , back to the actuating rod 7, guide rod sealing ring 8 and back to the sealing ring 9.

A rear cavity oil outlet hole 13 is provided at the bottom of the cylinder housing 1, a front cavity oil outlet hole 21 is opened on the cylinder head, and a disconnected rear cavity is opened in the side wall of the cylinder housing 1 and at the position corresponding to the cylinder head 2 The return hydraulic oil flow channel 14 and the front cavity sub-center return hydraulic oil flow channel 22. The actuating cylinder housing 1 is further provided with a first actuating cylinder housing centering hole 15 communicating with the rear cavity sub-centering hydraulic oil flow channel 14 and a second actuating cylinder communicating with the front cavity sub-centering hydraulic oil flow channel 22 The shell is returned to the center hole 16 . The center-returning actuating rod 7 is inserted into the center-returning hydraulic oil flow channel when assembled, and its outer end is connected with the piston rod 3 through the connecting bracket 4, and keeps synchronizing with the piston rod 3 during movement. The connection bracket 4 and the piston rod 3 are fastened by screws in the form of a shaft shoulder and a pressure plate 5, and the connection bracket 4 and the center return actuating rod 7 can be fastened by a shaft shoulder and a nut. There is a sealing groove in the middle of the centering hydraulic oil flow channel on the side wall of the actuating cylinder housing 1. During assembly, a centering sealing ring 9 is installed to make the rear cavity sub-centering hydraulic oil flow channel 14 and the front cavity sub-centering hydraulic oil flow channel. 22 oil is blocked. A guide rod sealing ring 8 is used on the cylinder head 2 to seal the return oil passage.

The center-returning actuating rod 7 is a hollow tubular structure, but it is not a through-pipe structure. A section of the center-returning actuating rod 7 close to the inner end of the blocking position is reserved. When the installation is completed, the outer end is blocked by the hydraulic plug 6 . The centering actuating rod 7 needs to ensure that when the piston rod 3 and the centering actuating rod 7 are kept in the centering position, the blocking position is at the centering hole 15 of the first actuating cylinder housing and the second actuating cylinder casing back between the holes 16. The center-returning actuating rod 7 is provided with an actuating rod oil inlet hole 71 , a second center-returning hole 74 , and a first-returning hole 75 of corresponding sizes to ensure that the center-returning actuating rod 7 flows through the front cavity when it is in the centering position. The high-pressure oil in the oil outlet hole 21 can enter the inner channel 72 of the centering actuating rod through the oil inlet hole 71 of the actuating rod, and finally pass through the second centering hole 74 and the first centering hole 75 on the actuating rod and actuate. The throttle hole combined by the first cylinder housing center return hole 15 and the second cylinder housing center return hole 16 on the cylinder housing 1 returns to the fuel tank.

As shown in Figure 4, when a fault occurs, the high-pressure oil enters the front and rear chambers from the oil inlet hole 11 of the rear chamber and the oil inlet hole 12 of the front chamber respectively from the mailbox through the control valve, and pushes the piston rod 3 to move. When returning to the center position, the high pressure oil in the left cavity passes through the oil outlet hole 13 of the rear cavity, the rear cavity sub-centering hydraulic oil flow channel 14, the inner end inlet 73 of the centering actuating rod, the first centering hole 75 and the first actuating cylinder. The shell return hole 15 flows back to the fuel tank, and the high pressure oil in the right cavity passes through the front cavity oil outlet hole 21, the front cavity sub-center return hydraulic oil flow channel 22, the actuating rod oil inlet hole 71, the middle return actuating rod internal channel 72, and the first The secondary return hole 74 and the second cylinder housing return hole 16 flow back to the external fuel tank. When the piston rod travels to the centering position, corresponding to different load forces, the centering hole 15 and the first centering hole 75 of the first cylinder housing and the centering hole 16 and the second centering hole 16 of the second cylinder housing The centering holes 74 are combined to form a corresponding flow area, and finally the force balance of the piston rod 3 is maintained to maintain the centering position.

As shown in Fig. 4, the principle of the centering of the actuating cylinder is as follows: under normal working conditions, the left cavity of the switching valve spool 104 is filled with high-pressure oil, the switching valve is located on the right side, and the throttle ports r ₁ and r ₂ are kept closed at this time. , the position of the piston rod 3 of the actuator is controlled by the servo valve 102; when the failure of the actuator is detected, the solenoid valve 103 is powered off, the high pressure oil in the left cavity of the switch valve spool 104 is unloaded, and the switch valve is switched to the left emergency return At this time, the throttle ports r ₁ and r ₂ are opened; the two cavities of the actuating cylinder are fed with high-pressure oil, and the first actuating cylinder casing is returned to the middle hole 15 and the second actuating cylinder casing is returned to the middle hole 16 Connected to external tank 106, the actuator piston returns to neutral.

The present invention adopts a wall hole return-to-center structure, which is simple in structure and differs from the prior art in that the oil enters the center-returning flow channel and the center-returning actuating rod through the oil holes at both ends of the actuator, and finally returns to the center-return hole through the guide rod. The combined throttle hole and the center return hole of the actuating cylinder shell flow back to the oil tank. The advantage of the present invention is that the center return hole of the actuating cylinder casing is not directly communicated with the working chamber of the actuator, which avoids scraping during the movement of the piston. , to ensure the reliability of the actuator under a long working state and improve its service life.

The above description of the embodiments is for the convenience of those skilled in the art to understand and apply the present invention. It will be apparent to those skilled in the art that various modifications to these embodiments can be readily made, and the generic principles described herein can be applied to other embodiments without inventive step. Therefore, the present invention is not limited to the embodiments herein, and improvements and modifications made to the present invention by those skilled in the art according to the disclosure of the present invention should all fall within the protection scope of the present invention.

Claims (9)

1. A hydraulic centering locking actuating cylinder structure comprises an actuating cylinder shell (1), a cylinder cover (2) and a piston rod (3), wherein the piston of the piston rod (3) divides the inner cavity of the actuating cylinder shell (1) into a front cavity and a rear cavity, and is characterized by further comprising a centering hydraulic oil flow passage and a centering actuating rod (7) which are arranged in the side wall of the actuating cylinder shell (1), the inner end of the centering actuating rod (7) is inserted into the centering hydraulic oil flow passage, the outer end of the centering actuating rod is fixedly connected with the outer end of the piston rod (3) through a connecting support (4) and synchronously acts with the piston rod (3), the centering actuating rod (7) is of a hollow tubular structure blocked at a blocking position, and the centering hydraulic oil flow passage is divided into a front cavity centering hydraulic oil flow passage (22) and a rear cavity centering hydraulic oil flow passage (14) which are respectively communicated with an external oil tank through an inner blocking section and an external centering sealing ring (9) at the blocking position, the plugging section is synchronous with the position of the piston.

2. The hydraulic centering locking cylinder structure according to claim 1, wherein the rear cavity is communicated with an external high-pressure oil source through a rear cavity oil inlet (11) and is communicated with a rear cavity sub centering hydraulic oil flow passage (14) through a rear cavity oil outlet (13), a first centering hole (75) is formed in the side wall of the inner end of the centering actuating rod (7), a first actuating cylinder shell centering hole (15) communicated with an external oil tank is formed in the side wall of the actuating cylinder shell (1), and the external high-pressure oil source, the rear cavity oil inlet (11), the rear cavity oil outlet (13), the rear cavity sub centering hydraulic oil flow passage (14), an inner end inlet (73) of the centering actuating rod, the first centering hole (75), the first actuating cylinder shell centering hole (15) and an external oil tank are mutually communicated in a circulating manner to form a rear cavity hydraulic centering loop.

3. The hydraulic centering locking cylinder structure according to claim 2, wherein the front chamber communicates with an external high pressure oil source through a front chamber oil inlet hole (12) and communicates with a front chamber sub centering hydraulic oil flow passage (22) through a front chamber oil outlet hole (21) provided in the cylinder head (2), the front chamber oil outlet hole (21) communicates with an outer end of a centering actuating rod internal passage (72) through an actuating rod oil inlet hole (71) provided in a side wall of a middle portion of the centering actuating rod (7), an inner end of the centering actuating rod internal passage (72) communicates with an external oil tank through a second centering hole (74) provided in a side wall of the centering actuating rod (7) and a second actuating cylinder housing centering hole (16) provided in a side wall of the actuating cylinder housing (1), and the external high pressure oil source, the front chamber oil inlet hole (12), the front chamber oil outlet hole (21), The front cavity sub-centering hydraulic oil flow passage (22), the centering actuating rod internal passage (72), the second centering hole (74), the second actuating cylinder shell centering hole (16) and an external oil tank are communicated with each other in a circulating mode to form a front cavity hydraulic centering loop.

4. The hydraulic centering locking cylinder structure as claimed in claim 3, wherein a sealing groove for placing the centering seal ring (9) is formed in the centering hydraulic oil flow passage.

5. A hydraulic centre-lock cylinder arrangement according to claim 4, characterised in that the sealing groove is located as centre-of-return between the first cylinder housing centre-of-return hole (15) and the second cylinder housing centre-of-return hole (16).

6. A hydraulic centering locking cylinder arrangement according to claim 1, characterized in that the connecting bracket (4) is fastened to the piston rod (3) by means of a pressure plate (5) and screws.

7. A hydraulic centering locking cylinder arrangement according to claim 1, characterized in that the outer end of the centering actuating rod (7) is blocked by a hydraulic plug (6).

8. A hydraulic centering locking cylinder arrangement according to claim 1, characterized in that the centering hydraulic fluid passage is provided with a guide rod seal (8) at the insertion opening of the centering actuating rod (7).

9. A hydraulic centre-return lock cylinder arrangement according to claim 1, characterised in that the piston rod (3) is balanced in force and maintained in the centre position when it is moved to the centre-return position.

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